Expansive reamer



J. J. SANTIAGO 2,227,763

EXPANSIVE HEAMER Filed Feb. 5, 1940 2 Sheets-Sheet 1 ZJ. qb( f uw C l 2 7 P m m4 4144x4424 www 4% nwrm ey m Y--- a j .k ..-2---. I, um MJ lllll /5 m 0/ 7 Z .444 m 0 wx 5% J 5 J .6 4576 w/f4 n w n# i -..rl|l|| Manus: 4 ...HU w o/ .I 4, Z a 7 2 4 44 4 4 w m a 5% 5 J d fa 5 m y w 4M /Z n /l PIII 4 HHHHH -n .Lkw ---MMU a? HW Jf /0 41 d 70 02u 5 44 44 an Vv 4 25 Wx A 5 w Jan. 7, 1941.

Jan. 7, 1941. J, J. SANTIAGO 2,227,763

EXPANSIVE BEAMER Filed Feb. 5, 1940 2 Sheets-Sheet 2 Patented Jan. 7, 1941 v UNITED sTATEs PATENT oFFicE EXPANSIVE REAMER James J. Santiago, Los Angeles. Calif., asslgnor to John Grant, Los Angeles, Calif.

Application February 5, 1940, Serial No. 317,326

7 Claims. (Cl. 255-76) My invention refers to expansive reamers of the pressure need. not be great, and the spring prestype used in deep wells, commonly known as unsure may be great enough to insure the return derreamers. In the past such reamers commonly of the hydraulic expander. have been expanded by either spring or hydraulic The nature o1' the invention, and how it per- 5 pressure action, and contracted by being pulled forms these operations, will be understood from into the casing, or contracted by spring action the following detailed description of an illustraafterV having been expanded by some! other action tive and preferred design, reference being had such as hydraulic. to the accompanying drawings, in which Various diiiculties have been encountered. In Fig. 1 is a vertical central section showing the the most common type of underreamer, expanded preferred form of my improved expansive reamer, lo by spring action and contracted by being pulled with its parts in the position which they assume into the casing. the spring expanding action conin passing up and down through the casing;

stantly presses the cutters outwardly, and when Fig. 2 is a similar section showing the cutters riding up and down through the casing there expanded for reaming operations below the may be considerable friction and wear. To recasing; 15

duce that friction and wear the spring pressure Fig. 3 is a similar section showing the parts must be kept at or near the minimum necessary 'in positions assumed during contraction of the to expand the cutters when they pass out o! the cutters; casing, and then there is present the liability Fig. 4 is a cross section on line 4--4 of Fig. l; that the cutters will not be expanded. Fig. 5 is a fragmentary vertical section showing 20 Hydraulic expansion has the advantage that a modified construction with the parts in the it is under control of the operator and therefore same position as shown in Fig. 1; and need not act to urge the cutters out until they Fig. 6 shows the modified structure in the posihave passed out of the casing and reached the tion of Fig. 2. J5 working zone. But the hydraulically actuated In the drawings the body of the tool is illus- 25 element, such as a plunger, must have some means trated as being made up of two parts, an upper to return it to its cutter retracting position; and part I0 and a lower tubular part II joined tosuch means may involve complications of strucgether at the threaded Joint I2. The tubular ture, or a connection between the cutters and body part Il is provided with cutter-receiving plunger such that considerable hydraulic presslots I3 through its walls, here shown as three 30 sure is required to hold the cutters expanded. in number. The cutters, which are referred to Or if a spring is used to retract the hydraulic generally by the numeral i4, may be of any type plunger, it must be strong enough to force reand have any kind of cutting edge, but are here traction with certainty, and the hydraulic presshown as composed of a cutter bar or carrier sure on the plunger must be correspondingly I5 and a cutter proper in the form ci a roller 35 high to expand the cutters and also overcome cutter I6 mounted on spindle I1 which is mounted the spring. High hydraulic pressures on the inthe bar or carrier I5. These cutters, specifactuating plungers are objectionablev because they ically the cutter carriers I5, t the body slots can only be attained by back pressures caused I3 rather snugly in width as is shown in Fig. 4; 40 by high velocities through restricted passages, but the slots I3 are considerably longer vertically 40 accompanied by rapid abrasion. than the cutters so that the cutters may move My invention in large measure overcomes the vertically between the position shown in Fig. 1 disadvantages of previous underreamers of both and the position shown in Fig. 3. types, and attains the advantages of both. By The inner parts of the cutter carriers as here utilizing controllable expansion it avoids the disshown are provided with vertically extending 45 advantage inherent in spring expansion of forcanges or lugs 20 which bear outwardly against ing the cutters to ride the casing. On the other the inner surface of tubular body member II hand, by utilizing a spring or other yielding when the cutters are expanded. In their conelement against which the cutters are contracted tracted position, as shown in Fig. 4, the cutters by pulling into the casing, the expansive power may bear inwardly against eachother throughout 50 of that spring is then used to return the hytheir vertical lengths, to thus provide a limit of draulic or other controllable expanding means to contraction. When the cutters expand, as in its cutter contractive position. In its expand- Fig. 2, they do so by tipping outwardly at their ing action the hydraulic means does not have upper ends, their lower ends Vremaining in conto work against the spring; and so the hydraulic tact' with each other and with the inner surface 55 l the vertically movable of the body, and their lower ends are thus internally radially supported. When expanded, their upper ends are internally radially supported by abutment against the expanding plunger head 25. The foregoing described typical construction of the cutters, their mounting in the body, and their manner of support, is shown in prior Grant patents, for instance in Patent No. 1,819,367, dated August 18, 1931; as are also the general features of the spring actuation of the cutters, in .and of itself, to be described. These constructions aie here described merely as illustrative and typical of known forms of underreamers to which my invention is applicable or which may form one of the sub-mechanism elements of the combination that constitutes my invention.

Below the cutters, and forming a support for them is a spring actuated cutter propeller 26. 'I'he form of this propeller which I prefer is shown in the drawings and comprises a hollow plunger 2l resting upon the cutter-actuating spring 2B which at its lower end rests upon any suitable support in the body, as for instance upon the pin end 29 of the bit 30 which is screw-threadedly attached to the lower end of the body. Tubular plunger 2'I rides vertically in a cylindric bore 3I in the lower part of body part I I, and is provided with packing 32 to make a fluid-tight joint. The central circulation pipe 33, which is here shown as being rigidly attached at its upper end to the plunger or piston 34, has its lower end extending downwardly through the upper end of the cutter propeller 26 and into the interior of the hollow plunger 21 of the cutter propeller. A packing gland is provided at 36 for a fluid-tight joint, and the follower member 3l of this packing gland constitutes, in the present specifically preferred design, the part of cutter propeller 26 which immediately engages and supports the lower ends of the cutters I4.

In prior underreamer designs of the type most nearly like the parts of my underreamer that have thus far been described (see for instance the Grant patent above referred to) the plunger head 25 has usually been relatively stationary with reference to the body, and in a position such as shown in Fig. 2. The cutters then expand by moving up and out to the relative position shown in Fig. 2, and contract by moving down and in as indicated in Fig. 3, the part 25 remaining stationary with relation to the body. In my improved underreamer I make this part 25 in the form of a relative memberspecifically a vertically movable plunger head-so that this cutter expanding plunger on the one hand and the cutter and spring actuating assembly on the other hand, are vertically movable relative to each other and to the body. I accomplish that relative vertical movement in my prefered design by making th part 25 as a plunger head, or a part of a plunger, which is movable vertically with reference to the body and the other parts, and is actuated vertically in one direction, here downwardly, by hydraulic pressure. It will however be understood that in the broader aspects of my invention this plunger head represents any suitable movable expanding means actuated by any controllable actuating means.

As illustrated in preferred form in the drawings plunger 34 has an upper cylindric guide part 46 which ts somewhat loosely in a bore 4I in the lower end of body part I0. Below the lower extremity of body part Ill, plunger 34 has an enlarged head 42, provided with suitable packing 43, and fitting and reciprocating in cylindric bore 44 in the upper portion of body part II. Below the head 42 the vertically reciprocable plunger 34 carries the downwardly tapering cutter expanding plunger head 25. 'I'he vertical movement of plunger 34 is such that plunger head 25 may be moved between the positions shown in Figs. 1 and 2, preferably being stopped on the body in its lower position. In its lower position, of Fig. 2, plunger head 25 lies between the upper ends of cutters I4 when those cutters are in their uppermost positions. In this position the upper ends of the inner surfaces of the cutters I4 bear back against the slightly tapered surface 25a of plunger head 25. 'I'he lower end of plunger head 25 has a more abruptly tapered surface 25h with which the correspondingly beveled surfaces I 4b of the cutters cooperate as hereinafter described.

The upper body portion `II! has a longitudinal circulation passage 45 taking fluid under pressure from the drill pipe and communicating with the upper end of plunger bore 4I. Thence the circulating fluid passes downwardly through the circulation pipe 33 and into the bore 3I in the lower part of the body, and thence through the circulation passage or passages 46. When circulation under pressure is set up, a. certain downward pressure, depending upon the .pressure maintained on the fluid and also upon the relative sizes of passage 45 and pipe 33, will be maintained downwardly upon the upwardly facing surfaces of plunger 34 and head 42, thus tending to force the whole plunger 34 and plunger head 25 downwardly.

The tool is put into the casing with its parts in the positions shown in Fig. 1, with plunger 34 in its upper position either above or supported on the upper ends of cutters I4. Cutters I4 are in their inward retracted positions, spring 28 holding them in their upper positions Where their upper ends are pressed upwardly against the upper ends of slots I3. In this contractedcondition the extreme diameter of the tool is slightly less than the internal diameter of the casing, and when the tool is lowered through the casing there is no forcible frictional contact of the cutters with the casing, as there are no appreciable forces exerted on the cutters tending to expand them.

When the cutters emerge from the lower end of the casing and the tool reaches the position at which it is desired to start the reaming operation, suilcient pressure is put upon the circulating uid to force the plunger 34 downwardly. The pressure taking surfaces of plunger 34, and the relative sizes of the circulation passages, are preferably such that when the circulating fluid is put under a normal or usual minimum circulating pressure, the plunger will be pressed downwardly with sufficient force to force the cutters outwardly against and into the formation. In the meantime the tool is being rotated, so that the cutters cut their way out into the formation until the cutters are kfully expanded. 'I'his condition of the parts is shown in Fig. 2. Underreaming may then procede by lowering the tool as it is rotated; and normally the circulation pressures will be continuously maintained and thus hold plunger 34 in its lower position. However, if the circulation pressure should momentarily lower or cease,` it will be noted that the tapering angle of surface 25a of plunger head 25 is small enough that the inward pressure of the cutters upon that surface will not directly force the plunger up.

When the plunger head 25 is forced down, the

more abruptly, tapered surface 25h first comes into contact with the corresponding surfaces I4b on the upper ends of the cutters, forcing the cutters outwardly until the innerV surfaces of the cutters are far enough out to ride` on the slightly tapered surface 25a of the plunger head. The last small part of the expansion takes place by coaction of the two last mentioned surfaces.

When it is desired to remove the tool from the well it is pulled upwardly until the upper ends of the expanded cutters come into contact with the lower end of the casing or with the casing shoe. Beveled surfaces I4c at the upper outer corners of the cutters then engage the lower end of the casing, or the lower end of theshoe which usually has a corresponding beveled surface; and the action of those surfaces tends to press the cutters inwardly as the tool is pulled up. Relative to the body the cutters are pressed downwardly and inwardly. Plunger 34 still remains in its lower position whether the circulation pressure is being kept up or not; as there is as yet no force exerted upon it to move it upwardly. ConsequentlyI thewcutters cannot be contracted until they are relatively pushed down, as indicated in Fig. 3 where the cutters are shown in a partially lowered and contracted position. At the end of the operation of pushing the cutters downwardly and inwardly, the plunger 34 is still substantially in the relative position shown in Fig. 3, but the cutters are down far enough that they are below plunger head 25 and are also fully collapsed. The cutters and the plunger head 25 then occupy the positions relative to each other shown in Fig. l, but with both plunger and cutters in their lower positions.

Immediately the parts reach the last described positions the cutters can pass up into the casing, and are urged upwardly by spring 28. Being then prevented from expanding by the surrounding casing, the cutters then move upwardly and move plunger 34 upwardly with them, reaching the relative positions shown in Fig. 1, and being then in the same positions that they occupied when the tool was lowered through the casing. The tool can then be removed from the casing in the same condition in which it was lowered, and without any forcible frictional contact of the cutters with .the casing.

The foregoing describes the normal mode of operation of my reamer. In that normal mode of operation it will be seen that the cutters are not expanded by any active action of spring 28 but by the active relative downward movement of plunger/34. During this expanding action the spring 28 performs only the non-moving function of holding the cuttersin their elevated positions. Expansion of the cutters, or tendency to expand,

consequently does not automatically take place when the cutters emerge from the casing, for the same reasons that the cutters are not urged outwardly against the casing during the lowering of the tool. Expansion is caused only by the operation of plunger 34 which is under the control of the operator.

contraction initially takes place by forcing the cutters downwardly and inwardly against the upward pressure of spring 28. This initial contractive action is, in itself, the same as the contractive action of the usual spring actuated underreamer. When the cutters have reached their lower and contracted positions, they then can be pulled up through the casing even if something has occurred to bind plunger 34 in its lower position. If plunger 34 4is accidentally held down, the contracting action of the tool, and its condition during removal through the casing, is the same as in the usual spring-actuated underreamer.' Thus, the tool can still be contracted and removed-even if the plunger should for any reason become stuck in its lower position.

However, the final action and function of spring 28, after the cutters have been contracted and lowered, is to move both thel cutters and the plunger up to their initial positions as shown in Fig. 1, with the cutters in their final contracted positions.

The coacting surfaces 25h of the plunger head and l4b of the cutters constitute a simple and preferred form of interconnective means between the expanding plunger and the cutters which have an angular action that will move the cutters outwardly when the plunger moves in one direction (down) and which will move the plunger oppositely (up) when the cutters move in that latter direction. Other forms of interconnection, per se, are known and can be used, for instance angular toggle link interconnection. The wedging surface form of interconnection has however the advantage of simplicity. For the functions specified its angle should be preferably around 30 to 45 to the horizontal; that is, the taper of surface 25h should be sufficiently abrupt that the cutters will not bind between the plunger and the casing, and at the same time sharp enough to force the cutters out when the plunger is moved down. The angle of 30 to 45 is a good median value; the smaller angle is perhaps preferable.

In Figs. 5 and 6 a modied structure is shown wherein all the parts are the same as in Figs. l, etc., except the operative angular connection between the plunger and cutters. Here a pivoted link or links |00, disposed angularly as shown, is pivoted at IUI to the plunger and at |02 to the cutter. In the normal contracted position of Fig. 1 the link stands at an angle to the vertical that corresponds to the angle of surface 25h (Fig. 1) to the horizontal. When the plunger moves down the cutter is forced out by the angular action of the link, until the link is in or near a horizontal position (with the cutter expanded) as in Fig. 6. In the latter position the cutter is laterally supported by the link and plunger in the same manner as it is supported by the nearly vertical surface 25a of the plunger in Fig. 2. And from the latter position the cutter, when drawn up against the casing, is moved down and in, substantially as it is in Fig. 3. If -it is considered that the pressure taking surfaces at' link pivots IUI and |02 are always at right angles tothe length of the link, it will be recognized that those surfaces in their changing positions correspond in position and function to the angular engaging surfaces 25a and 25h of Figs. 1, etc.

The downward force necessarily exerted by the plunger to expand the cutters need not be large.

The only force within the tool itself that holds the cutters in, is the frictional engagement of their upper ends with the upper ends of the body slots. This frictional force may be reduced'to a minimum by placing those upper surfaces at an angle to the length of the cutter. They are so shown in the drawings when the cutter is tilted outwardly. The plunger also must exert sufficient force to expand the cutters against the wall of the hole as they cut their way outwardly, and thus to dependably cause expansion. By making the taper of wedge surface 25o somewhat more sharp, the necessary plunger pressure may be kept at a minimum.

The plunger pressure does not have to overcome the force of the cutter supporting spring which returns the plunger to normal elevated position.

Because oi that, andfbecause the spring does not.

.tendant velocities aild wear'in the circulation pipe 3l may be Small,

I claim: Y l. An expansive reamer comprising in combination withi a body, a cutter movable vertically and transversely relative to the body, yielding means urging the cutter upwardly, a cutter expander movable vertically relative to the body, connective means between the expander and the cutter acting to move the cutter outwardly onv downward movement of the expander and to move the expander upwardly on upward movement ot the cutter, and means for moving the expander down.

2. An expansive reamer comprising in combi- =nation with a. body, a cutter movable vertically and transversely relative to the body, yielding means urging the cutter upwardly, a cutter .expanding plunger vertically movable in the body and having wedging means adapted on down- .ward movement to engage the cutter and move it outwardly relative to the. body, said wedging means lying at such an angle that vupward movement of the cutter caused upward movement of the plunger. and means for applying pressure to the plunger to move it down.

3. An expansive reamer comprising in combination with a body, a cutter movable vertically and transversely relative to the body yielding means urging the cutter upwardly. a cutter expanding plunger vertically movable in the body and having a wedge surface adapted on downward movement to engage the cutter and move it outwardly relative to the body. said wedge surface making an angle of approximately .30 to 45 vto the horizontal, and means for applying pressure to the plunger to move it down.

4. In an expensive reamer having a body, a cutter movable vertically and transversely relative to the body and having an external formation adapted to cause downward and inward movement of the cutter when itis moved upwardly -against the lower end of a well casing, and yielding means urging the cutter upwardly; the combination of cutter expanding means movable vertically relative to the body, coacting on downward movement with the cutter to expand it, and controllable means for applying pressure to said means to move it down.

5. In an expansive reamer having a body, a cutter movable vertically and transversely relative to the body 4and having an external formation adapted to cause downward and inward movement of the cutter when it is moved upwardly against the lower end of a well casing, and yielding means urging the cutter upwardly; the combination of a cutter expanding plunger movable vertically relative to' the body, and havl ing a downwardly and outwardly facing wedge "surface adapted to engage the cutter on down'- ward movement and move thecutte'r outwardly and adaptedtotransmit upward vertical movement from the cutter to the plunger, and means for applying pressure to the plunger to move it down.

6. In an expansive reamer having a body, a cutter movable vertically and transversely relative to the body and having an external formation adapted to cause downward and inward movement of the cutter when it is moved upwardly against the lower end of a well casing, and yielding means urging the cutter upwardly; the combination of a cutter expanding plunger movable vertically relative to the body and having a cutter engaging wedge surface which makes an angle of approximately 30 to 45 to the horizontal, and means for applying pressure to the plunger to move it down.-

7. In an expansive reamer having a body, a cutter movable vertically and transversely relative to the body and having an external formation adaptedto cause do'wnward and inward movement of the cutter when it is moved upwardly against the lower end of a well casing, and yielding means urging the cutter upwardly; the combination of a cutter expander movable vertically relative to the body and having a cutter engaging surface which makes an angle of approximately 30 to 45 to the horizontal, and controllable means for moving the expander down with relation to the body and the cutter.

JAMES J. SANTIAGO. 

